diff --git a/imageflow_core/src/codecs/mozjpeg.rs b/imageflow_core/src/codecs/mozjpeg.rs
index 1790fe12..e5432961 100644
--- a/imageflow_core/src/codecs/mozjpeg.rs
+++ b/imageflow_core/src/codecs/mozjpeg.rs
@@ -33,14 +33,20 @@ pub struct MozjpegEncoder {
     matte: Option<Color>
 }
 
+const DEFAULT_QUALITY:u8 = 75;
+
 impl MozjpegEncoder {
     // Quality is in range 0-100
     pub(crate) fn create(c: &Context, quality: Option<u8>, progressive: Option<bool>, matte: Option<Color>, io: IoProxy) -> Result<Self> {
         if !c.enabled_codecs.encoders.contains(&crate::codecs::NamedEncoders::MozJpegEncoder){
             return Err(nerror!(ErrorKind::CodecDisabledError, "The MozJpeg encoder has been disabled"));
         }
+
         Ok(MozjpegEncoder {
-            io, quality, progressive, matte,
+            io, 
+            quality: Some(u8::min(100,quality.unwrap_or(DEFAULT_QUALITY))), 
+            progressive, 
+            matte,
             optimize_coding: Some(true),
             defaults: Defaults::MozJPEG,
 
@@ -49,7 +55,9 @@ impl MozjpegEncoder {
 
     pub(crate) fn create_classic(c: &Context, quality: Option<u8>, progressive: Option<bool>, optimize_coding: Option<bool>, matte: Option<Color>, io: IoProxy) -> Result<Self> {
         Ok(MozjpegEncoder {
-            io, quality, progressive, matte,
+            io, 
+            quality: Some(u8::min(100,quality.unwrap_or(DEFAULT_QUALITY)))
+            ,progressive, matte,
             optimize_coding,
             defaults: Defaults::LibJPEGv6,
         })
@@ -103,7 +111,9 @@ impl Encoder for MozjpegEncoder {
             cinfo.set_optimize_coding(o);
         }
 
-        let chroma_quality = self.quality.unwrap_or(75) as f32; // Lower values allow blurrier color
+        let chroma_quality = self.quality.unwrap_or(DEFAULT_QUALITY) as f32; // Lower values allow blurrier color
+
+
         let pixels_buffer = unsafe {frame.pixels_buffer()}.ok_or(nerror!(ErrorKind::BitmapPointerNull))?;
         let max_sampling = PixelSize{cb:(2,2), cr:(2,2)}; // Set to 1 to force higher res
         let res = match pixels_buffer {
diff --git a/imageflow_core/tests/visuals.rs b/imageflow_core/tests/visuals.rs
index c0bd7336..2d653e8a 100644
--- a/imageflow_core/tests/visuals.rs
+++ b/imageflow_core/tests/visuals.rs
@@ -1087,6 +1087,7 @@ fn test_zoom_with_preshrink() {
 }
 
 
+
 #[test]
 fn webp_lossless_alpha_decode_and_scale() {
     let matched = compare(Some(IoTestEnum::Url("https://imageflow-resources.s3-us-west-2.amazonaws.com/test_inputs/1_webp_ll.webp".to_owned())), 500,
@@ -1240,6 +1241,37 @@ fn smoke_test_ignore_invalid_color_profile(){
     ).unwrap();
 }
 
+
+#[test]
+fn smoke_test_invalid_params(){
+
+    
+    let tinypng = vec![0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A, 0x00, 0x00, 0x00, 0x0D, 0x49, 0x48, 0x44, 0x52, 0x00,
+                       0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01, 0x08, 0x06, 0x00, 0x00, 0x00, 0x1F, 0x15, 0xC4, 0x89, 0x00,
+                       0x00, 0x00, 0x0A, 0x49, 0x44, 0x41, 0x54, 0x78, 0x9C, 0x63, 0x00, 0x01, 0x00, 0x00, 0x05, 0x00, 0x01,
+                       0x0D, 0x0A, 0x2D, 0xB4, 0x00, 0x00, 0x00, 0x00, 0x49, 0x45, 0x4E, 0x44, 0xAE, 0x42, 0x60, 0x82 ];
+
+
+    let steps = vec![
+        Node::CommandString{
+            kind: CommandStringKind::ImageResizer4,
+            value: "quality=957".to_owned(),
+            decode: Some(0),
+            encode: Some(1),
+            watermarks: None
+        }
+    ];
+
+    smoke_test(Some(IoTestEnum::ByteArray(tinypng)),
+               Some(IoTestEnum::OutputBuffer),
+               None,
+               DEBUG_GRAPH,
+               steps,
+    ).unwrap();
+}
+
+
+
 #[test]
 fn test_max_encode_dimensions(){